Colleagues and loved ones are remembering a 50-year-old man who died while trying to save two boys in Lake Michigan as a devoted father and skilled pediatric surgeon.

Dr. Donald Liu, a father of three, was on an outing with his family in Berrian County Mich., on Sunday morning when he saw two boys struggling to swim in the lake after falling off a kayak. Liu jumped into the lake but the strong rip current below pulled him under.

The boys, who were friends of the family, made it back to land but the doctor drowned.

Liu's wife, Dr. Dana Suskind, fondly remembered her husband as a dedicated surgeon, father and husband.

"It was horrible," Suskind told the Chicago Tribune. "He had the biggest heart. He was a brilliant surgeon … but what was amazing about him was that he was the best father, that was his priority in life, and he loved me with all of his heart."

The couple, married 17 years, met at the University of Pennsylvania where Liu was a third-year surgery resident and Suskind, also a surgeon, was an intern.

His skill for performing minimally invasive surgery and his work ethic garnered admiration from colleagues at University of Chicago Comer Children's Hospital.

They said he took on the hardest cases, helping sick children with cancer and other ailments, NBCChicago.com reported.

"He was a tireless, selfless physician," said Dr. John Alverdy, executive vice chairman of the department of surgery at the university. "He'd wake up at 2 a.m. to save a child from a gunshot wound, sleep for two hours and then be back here at 6 a.m. to do rounds and elective surgeries."

Liu joined the university in 2001 and was named chief of pediatric surgery and surgeon-in-chief at the hospital six years later. He had recently been awarded a "distinguished clinician" award.

"It lightened the atmosphere in the room and they were more open to you and all of a sudden you could see their faces light up," nurse practitioner Christopher Speaker said about how Liu interacted with sick children.